Communication networks, such as cellular based systems, typically have a plurality of cellular areas or cells wherein each cell provides service to a substantially circular geographical area. A base station is usually positioned centrally within the cell and is configured to conduct bi-directional communication with mobile or fixed remote cites within its coverage area. In a large geographical region a plurality of cells are arranged in a partially overlapping configuration to provide broad and continuous coverage to the area.
Typically, a base station controller will provide overall control of all the base stations in a particular geographical region or metropolitan area. One of the many functions of the base station controller is to provide a time stamp or synchronization signal to each base station in order that all units in the geographical area will have a common clock.
The base station controller will often be associated with one of the base stations in the geographic area, but it may also be at a location remote from all of the base stations. In any event, the distance between the base station controller and each of the base stations in the local geographic area controlled by the controller is unlikely to be exactly the same.
As noted above, the reference clock for each base station is derived from a master clock that is typically associated with the base station controller. Since the distance from the base station controller to each base station is not the same any propagation delay in the communication link (T1, E1, etc.) between the base station controller and each base station will mean that the time stamp for each base station will not be synchronized.
In prior art solutions, dedicated circuitry was included external to a multi-channel transceiver at the base station controller in an attempt to provide synchronization. In such systems proprietary hardware and software methods were used to achieve the required functionality. Alternatively, global position systems (GPS) based schemes have been used in certain implementations for achieving a similar functionality.